Sharp-edged cutting tools

ABSTRACT

Sharp-edged cutting tools and a method of manufacturing sharp-edged cutting tools wherein at least a portion of the sharp-edged cutting tool is formed from a bulk amorphous alloy material are provided.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is based on U.S. application Ser. No.60/274,339, filed Mar. 7, 2001, the disclosure of which is incorporatedby reference.

FIELD OF THE INVENTION

[0002] This invention is related to cutting tools constructed of bulksolidifying amorphous alloys, and more particularly to the blades ofcutting tools constructed of bulk solidifying amorphous alloys.

BACKGROUND OF THE INVENTION

[0003] It has long been known that the primary engineering challengesfor producing effective sharp-edged cutting tools are the shaping andmanufacturing of an effective sharp edge, the durability of the sharpedge against mechanical loads and environmental effects, and the cost ofproducing and maintaining sharp edges. As such, optimally the bladematerial should have very good mechanical properties, corrosionresistance, and the ability to be shaped into tight curvatures as smallas 150 Angstroms.

[0004] Although sharp-edged cutting tools are produced from a variety ofmaterials, each have significant disadvantages. For example, sharp-edgedcutting tools produced from hard materials such as carbides, sapphireand diamonds provide sharp and effective cutting edges, however, thesematerials have a substantially higher manufacturing cost. In addition,cutting edges of blades made from these materials are extremely fragiledue to the materials intrinsically low toughness.

[0005] Sharp-edged cutting tools made of conventional metals, such asstainless steel, can be produced at relatively low cost and can be usedas disposable items. However, the cutting performance of these bladesdoes not match that of the more expensive high hardness materials.

[0006] More recently it has been suggested to produce cutting tools madefrom amorphous alloys. Although amorphous alloys have the potential toprovide blades having high hardness, ductility, elastic limit, andcorrosion resistance at a relatively low cost, thus far the size andtype of blade that can be produced with these materials has been limitedby the processes required to produce alloys having amorphous properties.For example, cutting blades made with amorphous alloy are described inU.S. Pat. No. Re.29,989. However, the alloys described in the prior artmust either be manufactured in strips with thicknesses no greater than0.002 inch, or deposited on the surface of a conventional blade as acoating. These manufacturing restrictions limit both the types of bladesthat can be made from amorphous alloys and the full realization of theamorphous properties of these alloys.

[0007] Accordingly, there is a need for a cutting blade having goodmechanical properties, corrosion resistance, and the ability to beshaped into tight curvatures as small as 150 Angstroms

SUMMARY OF THE INVENTION

[0008] The subject of the present invention is improved sharp-edgedcutting tools, such as blades and scalpels made of bulk solidifyingamorphous alloys. The invention covers any cutting blade or toolrequiring enhanced sharpness and durability.

[0009] In one embodiment, the entire blade of the cutting tool is madeof a bulk amorphous alloys.

[0010] In another embodiment, only the metallic edge of the blade of thecutting tool is made of a bulk amorphous alloys.

[0011] In yet another embodiment, both the blade and the body of thecutting tool are made of a bulk amorphous alloy.

[0012] In still another embodiment, the bulk solidifying amorphous alloyelements of the cutting tool are designed to sustain strains up to 2.0%without any plastic deformation. In another such embodiment the bulkamorphous alloy has a hardness value of about 5 GPa or more.

[0013] In still yet another embodiment of the invention, the bulkamorphous alloy blades of the cutting tools are shaped into tightcurvatures as small as 150 Angstroms.

[0014] In still yet another embodiment of the invention, the bulkamorphous alloys are formed into complex near-net shapes either bycasting or molding. In still yet another embodiment, the bulk amorphousalloy cutting tools are obtained in the cast and/or molded form withoutany need for subsequent process such as heat treatment or mechanicalworking.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] These and other features and advantages of the present inventionwill be better understood by reference to the following detaileddescription when considered in conjunction with the accompanyingdrawings wherein:

[0016]FIG. 1 is a partial cross-sectional side view of a cutting bladein accordance with the present invention.

[0017]FIG. 2 shows a flow-chart of a process for making the cutting toolshown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention is directed to cutting tools wherein atleast a portion of the device is formed of a bulk amorphous alloymaterial, referred to herein as amorphous cutting tools.

[0019] Shown in FIG. 1 is a side view of a cutting tool 10 of thepresent invention. In general any cutting tool has a body 20 and a blade30. In such cutting tools the blade 30 is defined as that portion of thecutting tool which tapers to a terminating cutting edge 40, while thebody 20 of the cutting tool is defined as the structure that transfersan applied load from the cutting tool driving force to the cutting edge40 of the blade. In addition, as shown in FIG. 1, a cutting tool mayinclude an optional handle or grip 50 which serves as a stable interfacebetween the cutting tool user and the cutting tool. In such a case theportion of the body 20 to which the handle is attached is called theshank 60. The cutting tool of the present invention is designed suchthat the material for fabricating at least a portion of either the body,blade or both of the cutting tool is based on bulk-amorphous-alloycompositions. Examples of suitable bulk-amorphous-alloy compositions arediscussed below.

[0020] Although any bulk amorphous alloys may be used in the currentinvention, generally, bulk solidifying amorphous alloys refer to thefamily of amorphous alloys that can be cooled at cooling rates of as lowas 500 K/sec or less, and retain their amorphous atomic structuresubstantially. Such bulk amorphous alloys can be produced in thicknessesof 1.0 mm or more, substantially thicker than conventional amorphousalloys having a typical cast thickness of 0.020 mm, and which requirecooling rates of 10⁵ K/sec or more. Exemplary embodiments of suitableamorphous alloys are disclosed in U.S. Pat. Nos. 5,288,344; 5,368,659;5,618,359; and 5,735,975; all of which are incorporated herein byreference.

[0021] One exemplary family of suitable bulk solidifying amorphousalloys are described by the following molecular formula:(Zr,Ti)_(a)(Ni,Cu, Fe)_(b)(Be,Al,Si,B)_(c), where a is in the range offrom about 30 to 75, b is in the range of from about 5 to 60, and c inthe range of from about 0 to 50 in atomic percentages. It should beunderstood that the above formula by no means encompasses all classes ofbulk amorphous alloys. For example, such bulk amorphous alloys canaccommodate substantial concentrations of other transition metals, up toabout 20% atomic percentage of transition metals such as Nb, Cr, V, Co.One exemplary bulk amorphous alloy family is defined by the molecularformula: (Zr,Ti)_(a)(Ni,Cu)_(b)(Be)_(c), where a is in the range of fromabout 40 to 75, b is in the range of from about 5 to 50, and c in therange of from about 5 to 50 in atomic percentages. One exemplary bulkamorphous alloy composition is Zr₄₁Ti₁₄Ni₁₀Cu_(12.5)Be_(22.5).

[0022] Although specific bulk solidifying amorphous alloys are describedabove, any suitable bulk amorphous alloy may be used which can sustainstrains up to 1.5% or more without any permanent deformation orbreakage; and/or have a high fracture toughness of about 10 ksi-{squareroot}in or more, and more specifically of about 20 ksi-{square root}inor more; and/or have high hardness values of about 4 GPa or more, andmore specifically about 5.5 GPa or more. In comparison to conventionalmaterials, suitable bulk amorphous alloys have yield strength levels ofup to about 2 GPa and more, exceeding the current state of the Titaniumalloys. Furthermore, the bulk amorphous alloys of the invention have adensity in the range of 4.5 to 6.5 g/cc, and as such they provide highstrength to weight ratios. In addition to desirable mechanicalproperties, bulk solidifying amorphous alloys exhibit very goodcorrosion resistance.

[0023] Another set of bulk-solidifying amorphous alloys are compositionsbased on ferrous metals (Fe, Ni, Co). Examples of such compositions aredisclosed in U.S. Pat. No. 6,325,868, (A. Inoue et. al., Appl. Phys.Lett., Volume 71, p 464 (1997)), (Shen et. al., Mater. Trans., JIM,Volume 42, p 2136 (2001)), and Japanese patent application 2000126277(Publ. # 0.2001303218 A), incorporated herein by reference. Oneexemplary composition of such alloys is Fe₇₂Al₅Ga₂P₁₁C₆B₄. Anotherexemplary composition of such alloys is Fe₇₂Al₇Zr₁₀MO₅W₂B₁₅. Although,these alloy compositions are not as processable as Zr-base alloysystems, these materials can be still be processed in thicknesses around0.5 mm or more, sufficient enough to be utilized in the currentdisclosure. In addition, although the density of these materials isgenerally higher, from 6.5 g/cc to 8.5 g/cc, the hardness of thematerials is also higher, from 7.5 GPA to 12 GPa or more making themparticularly attractive. Similarly, these materials have elastic strainlimit higher than 1.2% and very high yield strengths from 2.5 GPa to 4GPa.

[0024] In general, crystalline precipitates in bulk amorphous alloys arehighly detrimental to their properties, especially to the toughness andstrength, and as such generally preferred to a minimum volume fractionpossible. However, there are cases in which ductile metallic crystallinephases precipitate in-situ during the processing of bulk amorphousalloys. These ductile precipitates can be beneficial to the propertiesof bulk amorphous alloys especially to the toughness and ductility.Accordingly, bulk amorphous alloys comprising such beneficialprecipitates are also included in the current invention. One exemplarycase is disclosed in (C.C. Hays et. al, Physical Review Letters, Vol.84, p 2901, 2000), which is incorporated herein by reference.

[0025] In one embodiment of the invention at least the blade 30 of thecutting tool is formed from one of the bulk amorphous alloys materialdescribed above. In such an embodiment, although any size and shape ofknife blade may be manufactured, it is desirable that the sharp cuttingedges 40 of the cutting tool have a radius of curvature as small aspossible for a high performing operation. As a bench mark, diamondscalpel blades can be produced with an edge radius of curvature lessthan 150 Angstroms. However, conventional materials pose severalobstacles during the process of shaping a cutting edge with such a smallradius. Conventional materials, such as stainless steel, have apoly-crystalline atomic structure, which is composed of smallcrystalline grains oriented in varying orientations. Because of thenonisotropic nature of these crystalline structures, the differentgrains in the material respond differently to the shaping operations, assuch, the shaping and manufacture of highly effective sharp edges fromsuch crystalline materials is either compromised or requires significantadditional processing raising the cost of the finished cutting tool.Because bulk solidifying amorphous alloys do not have a crystallinestructure, they respond more uniformly to conventional shapingoperations, such as lapping, chemical, and high energy methods.Accordingly, in one embodiment the invention is directed to cuttingtools having blades made of a bulk amorphous alloy material wherein thecutting edge 40 of the blade 30 has a radius of curvature of about 150Angstroms or less.

[0026] Because of the small radius of curvature of the cutting edges 40of these cutting tools, the edges have a low degree of stiffness, andare therefore subject to high levels of strain during operation. Forexample, cutting edges made of conventional metals, such as stainlesssteel, sustain large strains only by plastic deformation hence losingtheir sharpness and flatness. In fact, conventional metals startdeforming plastically at strain levels of 0.6% or less. On the otherhand, cutting edges made of hard materials, such as diamond, do notdeform plastically, instead they chip off due to their intrinsically lowfracture toughness, as low as 1 or less ksi-sqrt(in), which limits theirability to sustain strains over 0.6%. In contrast, due to their uniqueatomic structure amorphous alloys have an advantageous combination ofhigh hardness and high fracture toughness, therefore, cutting bladesmade of bulk solidifying amorphous alloys can easily sustain strains upto 2.0% without any plastic deformation or chip-off. Further, the bulkamorphous alloys have higher fracture toughness in thinner dimensions(less than 1.0 mm) which makes them especially useful for sharp-edgecutting tools. Accordingly, in one embodiment the invention is directedto cutting tool blades capable of sustaining strains of greater than1.2%.

[0027] Although the previous discussion has focussed on the use of bulksolidifying amorphous alloys in the blade portion of cutting tools, itshould be understood that bulk solidifying amorphous alloys can also beused as the supporting portion of the blades such as the body 20 of aknife or scalpel 10 as shown in FIG. 1. Such a construction is desirablebecause in cutting tools where the sharp edge has a differentmicrostructure (for higher hardness) than the microstructure of the bodysupport (which provide higher toughness though at substantially lowerhardness), once the sharp edge becomes dull, and/or resharpened a fewtimes, the blade material is consumed and the cutting tool must bediscarded. In addition, using a single material for both the body andblade reduces the likelihood of the different materials sufferingcorrosion, such as through galvanic action. Finally, since the body andblade of the cutting tool are one piece, no additional structure isneeded to attach the blade to the body so there is a more solid andprecise transfer of force to the blade, and, therefore, a more solid andprecise feel for the user. Accordingly, in one embodiment the inventionis directed to a cutting tool in which both the blade and the supportbody is made of a bulk amorphous alloys material.

[0028] In addition, in those cases in which a handle is formed on thebody of the cutting tool, although other materials may be mounted to thebody of the cutting tool to serve as a handle grip 50, such as plastic,wood, etc., the handle and body may also be constructed as a singlepiece made of a bulk amorphous alloy. Furthermore, although theembodiment of the cutting tool shown in FIG. 1 shows a traditionallongitudinal knife body 20 with a handle 50 attached on a long shank 60at the end of the body opposite the blade 30, any body configuration maybe made and, likewise, the handle may be positioned anywhere on the bodyof the cutting tool such that force applied from a user can betransmitted through the handle to the body to the blade and cutting edgeof the cutting tool.

[0029] Although cutting tools made of bulk amorphous alloys aredescribed above, the sharp-edges of the cutting tools can be made tohave a higher hardness and greater durability by applying coatings ofhigh hardness materials such as diamond, TiN, SiC with thickness of upto 0.005 mm. Because bulk solidifying amorphous alloys have elasticlimits similar to thin films of high hardness materials, such asdiamond, SiC, etc., they are more compatible and provide a highlyeffective support for those thin coatings such that the hardened coatingwill be protected against chip-off. Accordingly, in one embodiment theinvention is directed to cutting tools in which the bulk amorphous alloyblades further include a ultra-high hardness coating (such diamond orSiC) to improve the wear performance.

[0030] Although no finished cutting tools are discussed above, it shouldbe understood that the bulk amorphous alloy can be further treated toimprove the cutting tools' aesthetics and colors. For example, thecutting tool may be subject to any suitable electrochemical processing,such as anodizing (electrochemical oxidation of the metal). Since suchanodic coatings also allow secondary infusions, (i.e. organic andinorganic coloring, lubricity aids, etc.), additional aesthetic orfunctional processing could be performed on the anodized cutting tools.Any suitable conventional anodizing process may be utilized.

[0031] The invention is also directed to methods of manufacturingcutting tools from bulk amorphous alloys. FIG. 3 shows a flow-chart fora process of forming the amorphous alloy articles of the inventioncomprising: providing a feedstock (Step 1), in the case of a moldingprocess, this feedstock is a solid piece in the amorphous form, while inthe case of a casting process, this feedstock is a molten liquid alloyabove the melting temperatures; then either casting the feedstock fromat or above the melt temperature into the desired shape while cooling(Step 2a), or heating the feedstock to the glass transition temperatureor above and molding the alloy into the desired shape (Step 2b). Anysuitable casting process may be utilized in the current invention, suchas, permanent mold casting, die casting or a continuous process such asplanar flow casting. One such diecasting process is disclosed in U.S.Pat. No. 5,711,363, which is incorporated herein by reference. Likewise,a variety of molding operations can be utilized, such as, blow molding(clamping a portion of feedstock material and applying a pressuredifference on opposite faces of the unclamped area), die-forming(forcing the feedstock material into a die cavity), and replication ofsurface features from a replicating die. U.S. Pat. Nos. 6,027,586;5,950,704; 5,896,642; 5,324,368; 5,306,463; (each of which isincorporated by reference in its entirety) disclose methods to formmolded articles of amorphous alloys by exploiting their glass transitionproperties. Although subsequent processing steps may be used to finishthe amorphous alloy articles of the current invention (Step 3), itshould be understood that the mechanical properties of the bulkamorphous alloys and composites can be obtained in the as cast and/ormolded form without any need for subsequent process such as heattreatment or mechanical working. In addition, in one embodiment the bulkamorphous alloys and their composites are formed into complex near-netshapes in the two-step process. In such an embodiment, the precision andnear-net shape of casting and moldings is preserved.

[0032] Finally, the cutting tool blades are rough machined to form apreliminary edge and the final sharp edge is produced by one or morecombinations of the conventional lapping, chemical and high energymethods (Step 4). Alternatively, the cutting tool (such as knives andscalpels) can be formed from an amorphous alloy blank. In such a methodsheets of amorphous alloy material are formed in Steps 1 and 2, and thenblanks are cut from the sheets of bulk amorphous alloys 1.0 mm or morethickness in Step 3 prior to the final shaping and sharpening.

[0033] Although only a relatively simple single blade knife-like cuttingtool is shown in FIG. 1, it should be understood that utilizing such anear-net shape process for forming structures made of the bulk amorphousmetals and composites, more sophisticated and advanced designs ofcutting tools having the improved mechanical properties could beachieved.

[0034] For example, in one embodiment the invention is directed to acutting tool in which the thickness and or boundary of the cutting edgevaries to form a serration. Such a serration can be formed by anysuitable technique, such as by a grinding wheel having an axis parallelto the cutting edge. In such a process the grinding wheel cuts back thesurface of the metal along the cutting edge. This adds jaggedness to thecutting edge as shown forming protruding teeth such that the cuttingedge has a saw tooth form. Alternatively, the serrations may be formedin the molding or casting process. This method has the advantage ofmaking the serrations in a one-step. A cutting tool having a serratededge may be particularly effective in some types of cuttingapplications. Moreover the cutting ability of such a cutting tool is notdirectly dependant on the sharpness of the cutting edge so that thecutting edge is able to cut effectively even after the cutting edgewears and dulls somewhat.

[0035] Although specific embodiments are disclosed herein, it isexpected that persons skilled in the art can and will design alternativeamorphous alloy cutting tools and methods to produce the amorphous alloycutting tools that are within the scope of the following claims eitherliterally or under the Doctrine of Equivalents.

What is claimed is:
 1. A cutting tool comprising: a blade portion havinga sharpened edge and a body portion; wherein at least one of the bladeportion and the body portion are formed from a bulk amorphous alloymaterial.
 2. The cutting tool as described in claim 1, wherein the bulkamorphous alloy is described by the following molecular formula:(Zr,Ti)_(a)(Ni,Cu, Fe)_(b)(Be,Al,Si,B)_(c), wherein “a” is in the rangeof from about 30 to 75, “b” is in the range of from about 5 to 60, and“c” in the range of from about 0 to 50 in atomic percentages.
 3. Thecutting tool as described in claim 1, wherein the bulk amorphous alloyis described by the following molecular formula:(Zr,Ti)_(a)(Ni,Cu)_(b)(Be)_(c), wherein “a” is in the range of fromabout 40 to 75, “b” is in the range of from about 5 to 50, and “c” inthe range of from about 5 to 50 in atomic percentages.
 4. The cuttingtool as described in claim 1, wherein the bulk amorphous alloy isdescribed by the following molecular formula:Zr₄₁Ti₁₄Ni₁₀Cu_(12.5)Be_(22.5).
 5. The cutting tool as described inclaim 1, wherein the bulk amorphous alloy can sustain strains greaterthan 1.2% or more without any permanent deformation or breakage.
 6. Thecutting tool as described in claim 1, wherein the bulk amorphous alloyhas a high fracture toughness of at least about 10 ksi-{square root}in.7. The cutting tool as described in claim 1, wherein the bulk amorphousalloy has a high fracture toughness of at least about 20 ksi-{squareroot}in.
 8. The cutting tool as described in claim 1, wherein the bulkamorphous alloy has a high hardness value of at least about 4 Gpa. 9.The cutting tool as described in claim 1, wherein the bulk amorphousalloy has a high hardness value of at least about 5.5 GPa.
 10. Thecutting tool as described in claim 1, wherein the bulk amorphous alloyis based on ferrous metals wherein the elastic limit of the bulkamorphous alloy is about 1.2% and higher.
 11. The cutting tool asdescribed in claim 1, wherein the bulk amorphous alloy is based onferrous metals wherein the elastic limit of the bulk amorphous alloy isabout 1.2% and higher, and the hardness of the amorphous alloys is about7.5 Gpa and higher.
 12. The cutting tool as described in claim 1,wherein the bulk amorphous alloy is described by a molecular formulaselected from the group consisting of: Fe₇₂Al₅Ga₂P₁₁C₆B₄ andFe₇₂Al₇Zr₁₀MO₅W₂B₁₅.
 13. The cutting tool as described in claim 1,wherein the at least one portion formed from the bulk amorphous alloy isdesigned such that it does not undergo plastic deformation at strainlevels of at least about 1.2%.
 14. The cutting tool as described inclaim 1, wherein the at least one portion formed from the bulk amorphousalloy is designed such that it does not undergo plastic deformation atstrain levels of at least about 2.0%.
 15. The cutting tool as describedin claim 1, wherein the bulk amorphous alloy further comprises a ductilemetallic crystalline phase precipitate.
 16. The cutting tool asdescribed in claim 1, further comprising a handle mounted onto the bodyportion.
 17. The cutting tool as described in claim 16, wherein thehandle is formed from a material selected from the group consisting of:a plastic, a metal and wood.
 18. The cutting tool as described in claim1, wherein at least the blade portion portion is formed from the bulkamorphous alloy.
 19. The cutting tool as described in claim 1, whereinthe sharpened edge is formed from a bulk amorphous alloy and has aradius of curvature of about 150 Angstroms or less.
 20. The cutting toolas described in claim 1, wherein the blade portion is further coatedwith a high-hardened material selected from the group consisting of:TiN, SiC and diamond.
 21. The cutting tool as described in claim 1,wherein the cutting tool is anodized.
 22. The cutting tool as describedin claim 1, wherein the at least one portion formed from the bulkamorphous alloy has a thickness of at least 0.5 mm.
 23. The cutting toolas described in claim 1, wherein the cutting tool is in the form of oneof either a knife or a scalpel.
 24. The cutting tool as described inclaim 1, wherein the sharpened edge is serrated.
 25. A cutting toolcomprising: a blade portion having a sharpened edge and a body portion;wherein both the blade portion and the handle portion are formed from abulk amorphous alloy material.
 26. A method of manufacturing a cuttingtool comprising: forming blank from a bulk amorphous alloy; shaping theblank to form a blade portion and a body portion; and sharpening saidblade portion to form a sharpened edge.
 27. The method as described inclaim 26, wherein the bulk amorphous alloy is described by the followingmolecular formula: (Zr,Ti)_(a)(Ni,Cu, Fe)_(b)(Be,Al,Si,B)_(c), wherein“a” is in the range of from about 30 to 75, “b” is in the range of fromabout 5 to 60, and “c” in the range of from about 0 to 50 in atomicpercentages
 28. The method as described in claim 26, wherein the bulkamorphous alloy is described by the following molecular formula:(Zr,Ti)_(a)(Ni,Cu)_(b)(Be)_(c), wherein “a” is in the range of fromabout 40 to 75, “b” is in the range of from about 5 to 50, and “c” inthe range of from about 5 to 50 in atomic percentages.
 29. The method asdescribed in claim 26, wherein the bulk amorphous alloy is described bythe following molecular formula: Zr₄₁Ti₁₄Ni₁₀Cu_(12.5)Be_(22.5).
 30. Themethod as described in claim 26, wherein the bulk amorphous alloyfurther comprises a ductile metallic crystalline phase precipitate. 31.The method as described in claim 26, wherein the bulk amorphous alloy isbased on ferrous metals wherein the elastic limit of the bulk amorphousalloy is about 1.2% and higher, and the hardness of the amorphous alloysis about 7.5 Gpa and higher.
 32. The method as described in claim 26,wherein the bulk amorphous alloy is described by a molecular formulaselected from the group consisting of: Fe₇₂Al₅Ga₂P₁₁C₆B₄ andFe₇₂Al₇Zr₁₀MO₅W₂B₁₅.
 33. The method as described in claim 26, whereinthe both the blade and body portion are formed of a bulk amorphousalloy.
 34. The method as described in claim 26, wherein the bladeportion is sharpened such that the blade has a radius of curvature ofabout 150 Angstroms or less.
 35. The method as described in claim 26,wherein the step of forming one of the blade portion and handle portioncomprises one of the methods selected from the group consisting of:molding and casting.
 36. The method as described in claim 26, whereinthe step of forming one of the blade portion and body portion comprisescutting a blank from a sheet of bulk amorphous alloy formed by one ofthe methods selected from the group consisting of: molding, casting andthermoplastic casting.
 37. The method as described in claim 26, furthercomprising coating the blade portion with a high hardness materialselected from the group consisting of: SiC, diamond and TiN.
 38. Themethod as described in claim 26, further comprising mounting a handle tothe body portion of the cutting tool.
 39. The method as described inclaim 26, further comprising anodizing the cutting tool.
 40. The methodas described in claim 26, further comprising forming serrations on thesharpened edge.